Otitis media is a very common problem in general practice.

It is a term which describes two conditions which form part of a continuum of disease. Acute otitis media (AOM) and otitis media with effusion (OME). Both occur mainly in childhood and may be caused by bacterial or viral infection.

Most children will have a self-limiting illness and many will not present to a doctor. A few will have recurrent or chronic problems and may require referral.

As children grow bigger, the angle between the eustachian tube and the pharynx becomes more acute and so coughing or sneezing tends to push it shut. In small children, the less acute angle facilitates infected material being transmitted down the tube to the middle ear.

Epidemiology

Most children will experience some form of acute otitis media during their lifetime:

• The peak age of incidence is 6 months to 15 months old and it is rarely seen above 5 years of age.
• Otitis media occurs more in the winter than summer months as it is usually associated with a cold.
• It can occur in adults but this is most unusual.

Risk factors

• Boys are more likely than girls to develop otitis media with effusion.
• Children with older siblings at school or nursery are exposed to infections that may be brought home.
• Use of a dummy increases risk.¹ Presumably the sucking and swallowing opens the eustachian tube and puts the middle ear at risk.
• Children who suffer with many colds or respiratory infections are more likely to develop OME.
• Parent's smoking is thought to be associated with an increase in both acute and chronic otitis media.²

Presentation

Symptoms

AOM is a condition in which there is inflammation of the middle ear, frequently in association with an upper respiratory tract infection (URTI). It commonly presents with:

• Pain
• Malaise
• Irritability
• Fever
• Vomiting

The fever is often very high and may be associated with febrile convulsions.

Signs

Examination may reveal:

• Fever may be very high.
• Red and possibly bulging eardrums.
• Sometimes the outer ear glows red.
• Hearing loss is present but not usually noticed in an acutely unwell child.

A well-recognised complication is that a child who is screaming and in a great deal of pain finally settles and the ear starts to discharge green pus. The eardrum has burst, releasing the pressure and relieving the pain.

Differential diagnosis

• Otitis externa (OE)
• Post-auricular adenitis
• Referred pain (especially from teeth)
• Herpetic infection of ear
• Foreign body in external canal

Often children who are unwell have a slightly red eardrum but in AOM it is very red.

Investigations

• Usually no investigation is required.
• Culture of discharge from ear may be indicated in chronic or recurrent perforation.
• Audiometry should be performed if chronic hearing loss is suspected, but not during acute infection.

Management

The majority of cases of AOM will resolve spontaneously without specific treatment but a significant number will not. It can be difficult to decide who will need antibiotics and who will not. Pragmatic and evidence-based recommendations are made here from current sources.

Relief of pain

The primary objective of treatment is the relief of symptoms:

• Pain and temperature should respond to paracetamol or ibuprofen:
  • To get an adequate response, an adequate dose is required and parents are often rather reluctant to give the full, appropriate dose for the child's age
  • Paracetamol lasts only about 4 hours and needs repeating
  • Ibuprofen lasts 8 hours and so is useful through the night and many people feel that it may be more effective than paracetamol
• The child should not be wrapped up too much and should be allowed to lose heat. Often parents are reluctant to bring a child out on a cold night but after convincing, they do so, and the cold night air is beneficial and the child arrives less ill than when they left home.
  
  
• Parents often use eardrops to try to ease the pain:
  • Topical aqueous 2% lignocaine eardrops provide rapid relief for many young children presenting with ear pain attributed to AOM³
  • The concurrent use of simple oral analgesia is a likely contributor to effective management

The role of antibiotics

A Cochrane review concluded that:
"Antibiotics provide a small benefit for AOM in children.⁴ As most cases will resolve spontaneously, this benefit must be weighed against the possible adverse reactions. Antibiotic treatment may play an important role in reducing the risk of mastoiditis in populations where it is more common."

The trouble with reviews that find a small benefit overall is that there may be subgroups in which benefit is marked but this effect is diluted by the rest of the trial.

• One placebo-controlled trial found only a modest benefit in terms of symptom relief and failure rate, with the number needed to treat to prevent one treatment failure being 17.⁵
• Another found that to avoid clinical failure between 2 and 7 days required an NNT of 8.⁶
• A pragmatic compromise is to give a prescription for an antibiotic at the time, telling the parents to wait and see if it is necessary to have it dispensed.⁷
• A variation is to let the parents return at their own discretion in 72 hours to collect a prescription. The latter was recommended by SIGN.⁸ This is common practice in Holland and has been tried in the UK and USA.⁹ Only about a quarter of prescriptions are dispensed. Delayed prescription does reduce antibiotic consumption but the duration of delay varies amongst practitioners from 1 to 7 days.¹⁰

When organisms are isolated, the most common pathogens are S. pneumoniae (25%), H. influenzae(25%)and Moraxella catarrhalis(15%) and therefore, when antibiotics are used, a broad spectrum antibiotic such as amoxicillin, trimethoprim or erythromycin is most commonly used for a period of 5 days. Amoxicillin is still the antibiotic of choice.⁹

There may appear to be some logic in the use of antihistamines and other decongestants but there is no apparent benefit, whilst there is much potential for adverse effects and so they should not be used.¹¹ No evidence has been found to support the use of mucolytics, decongestants or inhaled steroids in otitis media.⁸

Who needs antibiotics?

Meta-analysis of randomised, placebo-controlled trials demonstrated that antibiotics increased resolution at 1 week by only 13%.⁹ However, the doctor is faced with a patient, not a statistic. Although the authorities constantly belittle the role of antibiotics in the disease, the NNTs given are not very high compared with many other conditions. Clinical Knowledge Summaries suggests that the following groups are more likely to benefit from antibiotics:¹²

• Child under 2 years of age.
• Bilateral AOM.
• Systemic symptoms, including high temperature (above 38.5 °C) or vomiting.
• Local signs that suggest the infection is severe, such as a particularly bulging or inflamed tympanic membrane.

Although not included in this list, the reader may like to include where the eardrum is obviously ruptured as there is pus draining from the ear.

The above may be summarised as follows:

• If the child is very hot and unwell and, especially if under 2, give antibiotic.
• If the child is only mildly unwell, hold back but be prepared to reconsider.
• If in doubt, use the delaying strategy.

This is in-keeping with a large meta-analysis¹³ that concluded that antibiotics seem to be most beneficial in children younger than 2 years of age with bilateral AOM, and in children with both AOM and otorrhoea. For most other children with mild disease an observational policy seems justified.

The Health Protection Agency and the BNF recommend a course of 3 to 7 days and SIGN recommends 5 days.¹²

If symptoms persist past 7 days, or reoccur within 14 days, treatment failure may have occurred and co-amoxiclav is the second line antibiotic if there is no allergy to penicillin.¹²

Further management

Children with a discharging ear or a perforated ear drum should be seen again in 2 or 3 weeks' time to check progress and be told to avoid getting water in the affected ear until then. If it is not fully resolved after 3 weeks, they should in a further interval of 2 or 3 weeks and at this stage any child with persistent problems should be referred for a specialist opinion, as should children with 4 or more episodes in 6 months.⁸ If pus is pouring from the ear, it will not be possible to see the drum but it is fair to assume that it must be ruptured.

A few children will go on to develop a degree of OME with impaired hearing and any child that is thought to have hearing problems should be referred for formal assessment with audiometry.

Children under the age of 3 who go on to develop OME with bilateral effusions and hearing loss of less than 25 decibels, but with no speech, language or developmental problems may be observed initially. Children over the age of three who go on to develop OME or with language or behavioural problems may benefit from surgical intervention such as the insertion of grommets and should be referred for a specialist opinion.¹⁴

Complications

• Most cases of AOM will resolve spontaneously with no sequelae.
• Perforation of the eardrum in not uncommon and progression to chronic suppurative otitis media may occur.
• Labyrinthitis, meningitis, intracranial sepsis or facial nerve palsy are very rare and occur in less than 1 in 1,000.⁶
• Recurrent episodes may lead to scarring of the drum with permanent hearing impairment, chronic perforation and otorrhoea, cholesteatoma or mastoiditis. In recurrent (either three or more acute infections of the middle ear cleft in a six-month period, or at least four episodes in a year) strategies for managing the condition include the assessment and modification of risk factors where possible, repeated courses of antibiotics for each new infection, antibiotic prophylaxis and the insertion of ventilation tubes (grommets). Grommets have a significant role in maintaining a 'disease-free' state in the first six months after insertion.¹⁵
• In a small child with a high temperature there is a risk of febrile convulsions. This is discussed more fully in its own article.

Prognosis

With the exception of the few complications given above, there is usually complete resolution in a few days.

Prevention

In children at high risk of recurrent AOM there may be benefit from prophylactic antibiotics. A Cochrane review¹⁶ found that for children at risk, antibiotics given once or twice daily will reduce the risk while the child is on treatment. The average incidence falls from around 3 to around 1.5 episodes per year. Larger absolute benefits are likely in high-risk children.

Pneumococcal vaccine does not appear to be beneficial in reducing the incidence of otitis media.¹⁷